1. Field of the Invention
The present invention relates to an electron-emitting device that is used for a flat panel display, and a manufacturing method of the electron-emitting device.
2. Description of the Related Art
A surface conduction electron-emitting device utilizes a phenomenon such that electron-emission is generated by applying a current on a film surface of a conductive film of a small area that is formed on a substrate in parallel. It has been popular that an electron emission portion is formed on the conductive film of the surface conduction electron-emitting device in advance by a conducting process (a forming). Specifically, the electron emission portion is formed by applying a direct voltage or a very slow boost voltage (for example, about 1 V/minute) to the opposite ends of the conductive film. Thereby, the conductive film is locally damaged, transformed, or modified, and then, as an electron emission portion, an electrically high resistive part is formed. Further, due to this forming, a gap is formed on a part of the electron emission portion of the conductive film. The electron is emitted from the vicinity of the gap.
In an image display apparatus to be formed by using a plurality of such electron-emitting devices, it is necessary to equalize an electron emission characteristic of the electron-emitting device. For this, an art to form a gap on a predetermined position of the conductive film is required.
In Japanese Patent Application Publication (JP-B) No. 2627620, a method of forming a stenosis portion for focusing a current by removing a part of the conductive film and forming a gap in the stenosis portion is disclosed. In JP-B No. 3647436, a method of forming a gap, by differentiating a width at a connection part of one electrode and the conductive film and a width at a connection part of other electrode and the conductive film, in the vicinity of an electrode on the side of which width at the connection part is shorter is disclosed.
However, according to any of the methods disclosed in JP-B No. 2627620 and JP-B No. 3647436, forming a stenosis portion in the conductive film, then, a gap is formed in the stenosis portion. In such a method, it is hard to elongate the length of the gap because space efficiency is lowered (namely, a space needed for mounting the conductive film is made large).